This invention relates generally to the field of telephony, and more particularly to an improved compact wall mounted distributing frame particularly adapted to terminate and protect incoming pairs at the subscriber location.
In the last several decades, there has been markedly increased use of customer-owned equipment at the customer location. This includes not only relatively simple devices such as recorders, but, as is the case with larger organizations, it is common to provide private automatic exchanges for direct telephone communication, as well as key systems, both of which require substantially sized crossed connect fields. As is to be expected, the telephone companies have provided for adequate protection of their incoming lines to prevent damage to expensive telephone office equipment, in the form of exposure to excess current surges caused by falling power lines, lightning strikes and the like. The companies also provide a measure of protection at the point of entry to the subscriber building, but such protection, usually designed and manufactured many years ago, is totally inadequate for the protection of sophisticated equipment, much of it with solid state electronic circuits, now installed by subscribers.
There are problems inherent in the installation of on site protection which are not present in the installation of central office equipment. Among these are substantial space limitations, and the high labor costs inherent in wire stripping, wire wrapping and soldering of connections. There is also the problem of tampering with circuits which are exposed in areas outside the control of the subscriber, example being common hallways and passageways.